C. Reinke wrote:
[...] I found that I had to move the call to genLists after createWindow.
I'd expect that, because most (all?) versions of GLUT don't initialize the OpenGL context until the window has actually been created. [...]
Exactly, I just had a look in the GLUT sources. So the general rule of thumb is:
Issue OpenGL calls *after* the first createWindow, never before.
Isn't that an argument against the displayFunc parameter to HOpenGL's createWindow? One could still have a createSimpleWindow or something for simple applications, but why pass and install a null handler if one most certainly needs to replace it soon?
This makes sense perfectly: Remember that you could have multiple Windows, so the effect of e.g. setting the current to color depends on the current GLX/OpenGL context. The latter one is created with createWindow, changed with e.g. setWindow, overlay handling, etc. etc.
I was fooled by display lists - while their drawing commands aren't executed until they are called, the implicit state queries that determine how a vertex will appear when drawn are executed at construction time:-( Hence they also suffer from the dependency you describe. Btw, is this foreign import shutdownHaskellAndExit :: Int -> IO () going to be standard Haskell/FFI/xx ? The earlier discussion here mentioned some hs_exit instead, but it wasn't clear whether that would make it into the addendum, either. Ah, the FFI release candidate 3 mentions hs_exit in section "6.1 CForeign" - is that the way to go then? Claus